Simply put, CRM validation rules support only a single condition for each field on "All Records". You also cannot specify additional validation rules on the same field because it has already been used in an existing validation rule. The ONLY solution if you wish to have more than one condition is to create a custom function. For example, you want only 10 characters and also number only. This can only be done with two conditions. And before you say you can just edit the default system field character length, you cannot. It is fixed at 50 characters. Sure, you could create a new field but then that field is not represented in system defined areas where the default phone field is represented.
Yes, you can specify more than one condition for the same validation rule...but only if you specify a subset of records using criteria. You cannot for "All Records".
In contrast, Desk has the ability to apply multiple conditions for the same validation rule. In fact, Desk also implemented using RegEx (regular expression) in their rules. Even if CRM maintains a single condition for its validation rules, adding at least RegEx would cut down on a ton of requests to support(at)zoho.com for custom functions having to do with validation rules. I understand RegEx well but not deluge. Even an inexperienced RegEx user can use online tools to generate spefici validations.
Please implement additional validation rule conditions for "All Records". Or, add regular expression validation condition as an option. Both of which desk has already implemented.
Because CRM is a more established and seasoned platform than Desk, I would have expected these features to be implemented in CRM first.
Regards,
Drew